program Project1;

{$APPTYPE CONSOLE}

var
    Numbers: array [0 .. 6] of cardinal = (
        9,
        0,
        8,
        2,
        7,
        1,
        6
    ); // Smallest unused cardinal in this list is 3

function FindSmallestUnusedCardinal(const aArray: array of cardinal): cardinal;
var
    i: integer;
begin
    Result := 0;

    while (True) do
    begin
        for i := 0 to Length(aArray) - 1 do
        begin
            if (aArray[i] = Result) then
            begin
                Inc(Result);
                Break;
            end;
        end;
        if (i = Length(aArray)) then
            Break;
    end;
end;

begin
    WriteLn('Found: ', FindSmallestUnusedCardinal(Numbers));
    ReadLn;
end.